Device for lifting boats



Den 3, 1957 J. E. LUNSMAN El'A-L 2,8

DEVICE F03 LIFTING BOATS Filed March 20, 1953 2 Sheets-Sheet 1 INVENTOR.Moe/WA /v Zu/vsMA/v Dec. 3, 1957 J. E. LUNSMAN ETAL DEVICE. FOR LIFTINGBOATS 2 Sheets-Sheet 2 Filed March 20, 1953 INVENTOR.

United States Patent thee 2,815,131 DEVICE FOR LIFTING BOATS John E.Lunsman and Norman F. Lunsman, Danbury, Wis., assignors to LunsmanManufacturing Company, Inc., Daubury, Wis.

Application March 20, 1953, Serial No. 343,688 1 Claim. (Cl. 214-1) Thisinvention relates to boat handling devices. invention, morespecifically, lifting small boats from the upon their sides.

The desirability of a structure usable as set forth above is wellappreciated. However, previous devices conceived for the same purposehave not, to our knowledge, found wide spread commercial favor. Webelieve this may be due to the fact that many of the prior art deviceshave been undesirably complex. Others, we believe, do not act withsuitable speed and efiiciency upon a boat floating in the water, tohoist said boat and tilt the same on its side.

In view of the above, we have devised a boat lift which, summarizedbriefly, includes a main frame which can be mounted upon a dock,landing, or the like, adjacent a body of water.

Hingedly mounted on said frame, to swing in vertical planes, are boatsupport arms. These swing downwardly into positions in which they extendtransversely of, and overlie, a boat floating in the water. When saidarms are in these positions, flexible elements, end to the main frameand normally connected at their The has regard to a device for water andturning said boats may include reduction gearing, is then utilized toswing the arms and the supported boat upwardly, while tilting the boaton its side.

Among important objects of the invention are the following:

To devise an improved boat lift and turning device that can bemanufactured at a minimum of cost and which will be of simple design;

To speed up and make easier the task of engaging the boat for lifting;

To devise a structure for the purpose set forth above which will beadapted to act upon boats of various sizes and types; and

To facilitate the lifting of boats to positions in which they can bereadily repaired, cleaned, or maintained.

Other objects will appear from the following description, the claimsappended thereto, and from the annexed drawings, in which like referencecharacters designate like parts throughout the several views, andwherein:

Figure 1 is a perspective view of a boat lifting and turning deviceformed in accordance with the present invention, as it appears whenready to lift a boat out of the water;

Figure 2 is an end elevational view, portions being broken away, thedotted lines showing the boat position after the boat has been lifted;

Figure 3 is an enlarged, detail sectional view taken on line 3-3 ofFigure 2, showing the means for swinging the boat support arms upwardlyand downwardly; and

Figure 4 is an enlarged, detail sectional view on line 'Manuallyoperated means on the main frame, which means 2,815,131 Patented Dec. 3,1957 44 of Figure 2, showing the connections of the boat support arms tothe main frame.

The reference numeral 10 has been applied generally to a dock, landing,wharf, or the like. The reference numeral 12 has been applied generallyto the lifting device constituting the present invention, and at 14 wehave designated a conventional boat to be lifted.

The lifting device 12 includes a stationary, open main frame generallydesignated 16 having, at opposite ends thereof, tubular, vertical posts18. Posts 18 are welded or otherwise rigidly connected, at their lowerends, to feet 20, which can be bolted to the landing 10.

Rigid at its opposite ends with, and extending between, the lower endportions of posts 18 is a lower longitudinal brace bar 22. An upperlongitudinal brace bar 24 is rigid at its opposite ends with the upperends of posts 18, and extends in parallelism with the horizontal bar 22.

Transverse brace members 26 are fixedly connected at one end to thelower ends of the respective posts 18. inclined braces 28 are fixedlyconnected at one end to the other ends of the transverse braces 26. Theinclined braces 28 are rigid, at their other ends, with the upper endsof the posts 18.

Base blocks 30 underlie the rear ends of the brace members 26, 28, andprovide means to which said rear ends can be bolted or otherwise fixedlyattached.

From the description so far provided, it is seen that we utilize astationary main frame having a vertically disposed front portion formedas an open, rectangular framework and comprised of posts 18, and bars22, 24.

We believe that although the main frame 12 has been illustrated as beinganchored to the landing, it might, quite possibly, be rollably mounted,for movement to selected locations. In these instances, the main framecould be chocked up at a particular location at which a boat is to belifted from or returned to the water. Of course, if the main frame wererollably mounted, it would be necessary that weight be applied in thearea of the rear ends of transverse braces 26, to counterbalance theboat 14.

An elongated, horizontally disposed shaft 32 is journaled at itsopposite ends in bearings 34, a short distance below the upperlongitudinal brace bar 24. One bearing 34 is mounted upon a bearingsupport plate 36 of right angled cross section, fixedly secured to theupper end portion of one post 18. The other bearing 34 (Figure 3) ismounted upon the vertically disposed, inwardly turned flange 38 of thevertical leg of an angular gear support plate 40. Gear support plate 40has its vertical leg secured fixedly to the other post 18, thehorizontal leg of said plate 40 extending to and being rigidly connectedto the adjacent inclined brace 28.

Referring to Figure 3, the horizontal leg of plate 40 has an inturnedlongitudinal flange 42 on which is mounted a bearing 44 for the shaft ofa small drive gear 46, said shaft having a crank 48 rigid therewith. Inmesh with the gear 46 is a larger, driven gear 50, secured to one end ofthe shaft 32. A pawl 52 is pivotally mounted upon the upper end of plate40, and gravitates, normally, to a position in which it will preventrotation of the gear 50in one direction.

Fixedly attached to shaft 32, adjacent opposite ends thereof, are drums54, and wound upon said drums are lifting cables 56 secured to the outerends of boat support arms 58. Arms 58, at their inner ends, havetransverse openings through which extend hinge bolts 60, said hingebolts passing through the forwardly projected ears 62 of hinge sleeves64 rotatably mounted upon the lower longitudinal brace bar 22.

Secured at one end to the respective sleeves 64 are flexible elements66. Elements 66 normally are connected, at their other ends, tostandards 68 mounted in 58 have been lowered to the spaced relation tothe landing 10, in the water. The length of elements 66 is such as topermit a boat to be fioated thereover, when said elements 66 areconnected to standards 68.

In use of the device, a boat 14 would be first floated into positionover the respective elements 66. Elements 66 are then detached fromstandards 68, and are attached to the outer ends of the boat supportarms 58, after arms positions shown in Figure 1.

The boat, and the associated parts of the boat lift, will now appear asshown in full lines in Figures 1 and 2. The crank 48 is then rotated, ina direction that will cause the arms 58 to be swung upwardly to thedotted line positions shown in Figure 2. The boat is thus lifted fromthe water, and tilted transversely to facilitate cleaning, maintenanceand the repair thereof.

The pawl 52, of course, prevents rotation, normally, of the gear 50 in adirection that would tend to unwind the cables 56 while the boat is inits lifted position.

It is believed apparent that the invention is not neces sarily confinedto the specific use or uses thereof described above, since it may beutilized for any purpose to which it may be suited. Nor is the inventionto be necessarily limited to the specific construction illustrated anddescribed, since such construction is only intended to be illustrativeof the principles of operation and the means presently devised to carryout said principles, it being considered that the invention comprehendsany minor change in construction that may be permitted within the scopeof the appended claim.

What is claimed is:

A boat lift comprising a main frame; a plurality of rigid arms connectedat one end thereto for vertical swinging movement about a commonhorizontal axis; U-shaped, flexible slings depending from and connectedat their opposite ends to the respective arms, to support a boatthereagainst during swinging movement of the arms; and standardsstationarily mounted in vertical positions, said standards correspondingin number to the several arms and being disposed outwardly from and inclosely spaced relation to the are described by the other ends of thearms during swinging movement of the arms, said slings being detachablyconnected at least at one end thereof to the arms for selectiveconnection of the slings to the standards and arms respectively.

References Cited in the file of this patent UNITED STATES PATENTS207,166 Dunn Aug. 20, 1878 1,061,213 Arbuckle May 6, 1913 1,116,761Thompson Nov. 10, 1914 1,192,158 Binks July 25, 1916 1,300,567 BrorbyApr. 15, 1919 1,429,432 Irrgang Sept. 19, 1922 2,185,083 Horton Dec. 26,1939 2,294,864 Palmer Sept. 1, 1942 2,465,118 Platt Mar. 22, 19492,552,424 Gorman May 8, 1951 2,581,676 Loaney Jan. 8, 1952 2,632,900Voigt 1 Mar. 31, 1953

